#include "stdio.h"
#include "encryptAES.h"
void encryptAES(short state[17], short key[17]){
	__int16 extendedKey[177];
	int xoringBase = 0;
	extendKey(key,extendedKey);
	for(int i = 0; i<16; i++){
		state[i] = state[i] ^ key[i];
	}
	xoringBase += 16;
	for(int i = 0; i<9; i++){
		subBytes(state);
		shiftRows(state);
		mix_column(state);
		for(int i = 0; i<16; i++){
			state[i] = state[i] ^ extendedKey[i + xoringBase];
		}
		xoringBase += 16;
	}
	subBytes(state);
	shiftRows(state);
	for(int i = 0; i<16; i++){
		state[i] = state[i] ^ extendedKey[i + xoringBase];
	}
}
void decryptAES(short state[17], short key[17]){
	__int16 extendedKey[177];
	int xoringBase = 160;
	extendKey(key,extendedKey);
	for(int i = 0; i<16; i++){
		state[i] = state[i] ^ extendedKey[xoringBase+i];
	}
	xoringBase -= 16;
	for(int i = 0; i<9; i++){
		invShiftRows(state);
		invSubBytes(state);
		for(int i = 0; i<16; i++){
			state[i] = state[i] ^ extendedKey[i + xoringBase];
		}
		xoringBase -= 16;
		inv_mix_column(state);
	}
	invSubBytes(state);
	invShiftRows(state);
	for(int i = 0; i<16; i++){
		state[i] = state[i] ^ extendedKey[i + xoringBase];
	}
}
void extendKey(__int16 key[17], __int16 extendedKey[177]){
	__int16 Rcon[10] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };
	//copy key to extendeKey
	for(int i=0; i<16; i++){
		extendedKey[i] = key[i];
	}
	//key schedule
	for(int kNo = 1;  kNo<11; kNo++){
		int keyRoot = kNo*16;
		int prevKeyRoot = (kNo-1)*16;
		//getting keyRoot
		//rotate
		extendedKey[keyRoot] = extendedKey[prevKeyRoot+7];
		extendedKey[keyRoot+4] = extendedKey[prevKeyRoot+11];
		extendedKey[keyRoot+8] = extendedKey[prevKeyRoot+15];
		extendedKey[keyRoot+12] = extendedKey[prevKeyRoot+3];

		//subBytes
		s_box(&extendedKey[keyRoot]);
		s_box(&extendedKey[keyRoot+4]);
		s_box(&extendedKey[keyRoot+8]);
		s_box(&extendedKey[keyRoot+12]);

		//Xoring
		extendedKey[keyRoot] = extendedKey[keyRoot] ^ Rcon[kNo-1] ^ extendedKey[prevKeyRoot];
		extendedKey[keyRoot+4] = extendedKey[keyRoot+4] ^  extendedKey[prevKeyRoot+4];
		extendedKey[keyRoot+8] = extendedKey[keyRoot+8] ^  extendedKey[prevKeyRoot+8];
		extendedKey[keyRoot+12] = extendedKey[keyRoot+12] ^  extendedKey[prevKeyRoot+12];
		for(int wNo = 1; wNo<4; wNo++){
			extendedKey[keyRoot+wNo] = extendedKey[keyRoot+wNo-1] ^ extendedKey[prevKeyRoot+wNo];
			extendedKey[keyRoot+wNo+4] = extendedKey[keyRoot+wNo+3] ^ extendedKey[prevKeyRoot+wNo+4];
			extendedKey[keyRoot+wNo+8] = extendedKey[keyRoot+wNo+7] ^ extendedKey[prevKeyRoot+wNo+8];
			extendedKey[keyRoot+wNo+12] = extendedKey[keyRoot+wNo+11] ^ extendedKey[prevKeyRoot+wNo+12];
		}
	}
}
void invS_box(_int16* sX){
	static const unsigned char inv_s[256] = 
	{
		0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
		0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
		0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
		0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
		0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
		0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
		0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
		0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
		0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
		0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
		0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
		0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
		0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
		0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
		0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
		0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D
	};
	*sX = inv_s[*sX];
}
void s_box(_int16* sX){
	static const unsigned char s[256] = 
	{
		0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
		0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
		0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
		0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
		0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
		0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
		0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
		0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
		0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
		0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
		0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
		0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
		0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
		0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
		0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
		0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16
	};
	*sX = s[*sX];
}
void invSubBytes(__int16 state[17]){
	for(int i = 0; i<16; i++){
		invS_box(&state[i]);
	}
}
void subBytes(__int16 state[17]){
	for(int i = 0; i<16; i++){
		s_box(&state[i]);
	}
}
void invShiftRows(__int16 state[17]){
	__int16 temp = 0;
	for(int i = 0; i < 4; i++){
		int j = i;
		while(j>0){
			int i1 = i<<2;
			temp = state[i1+3];
			state[i1+3] = state[i1+2];
			state[i1+2] = state[i1+1];
			state[i1+1] = state[i1];
			state[i1] = temp;
			j--;
		}
	}
}
void shiftRows(__int16 state[17]){
	__int16 temp = 0;
	for(int i = 0; i < 4; i++){
		int j = i;
		while(j>0){
			int i1 = i<<2;
			temp = state[i1];
			state[i1] = state[i1+1];
			state[i1+1] = state[i1+2];
			state[i1+2] = state[i1+3];
			state[i1+3] = temp;
			j--;
		}
	}
}
void mix_column(short * p_output)
{
	short time = 0; // used as a counter which is used to separate columns from input.
	short tempArray[4]; // used to hold each column from the input per time.
	while (time < 4)
	{
		short index = 0; // used as counter in various ways.
		while (index < 4)
		{
			tempArray[index] = p_output[time + (index << 2)]; // copying the column from the input to the temporary array.
			index += 1;
		}

		// multiplication operation starts from here.
		short tempValue = tempArray[0] ^ tempArray[1] ^ tempArray[2] ^ tempArray[3];
		index = 0;
		while (index < 4)
		{
			short value = ((tempArray[index] ^ tempArray[(index + 1) % 4]) << 1);
			if (value > 0xFF) value = (value ^ 0x1B) & 0xFF; // used as a compensator since we are now using x64 processors.
			p_output[time + (index << 2)] = tempArray[index] ^ tempValue ^ value;
			index += 1;
		}
		// end of emultiplication operation for a single column.

		time += 1;
	}
}
short multiply_number_number(short num1, short num2) 
{
	short result = 0x00, shifter = 0x01;
	if (shifter & num1) result = num2;
	while (!(shifter & 0x10))
	{
		shifter <<= 1;
		if (num2 & 0x80)
		{
			num2 <<= 1;
			num2 &= 0xFF;
			num2 ^= 0x1B;
		}
		else
		{
			num2 <<= 1;
		}
		if (shifter & num1) result ^= num2;
	}
	return result;
}
void inv_mix_column(short * p_output)
{
	int time = 0;
	short tempArray[4];
	short constant[16] = {
		0x0E, 0x0B, 0x0D, 0x09,
		0x09, 0x0E, 0x0B, 0x0D,
		0x0D, 0x09, 0x0E, 0x0B,
		0x0B, 0x0D, 0x09, 0x0E
	};
	while (time < 4)
	{
		// making a copy of the every column of the input
		for (int counter = 0; counter < 4; counter += 1)
		{
			tempArray[counter] = p_output[time + (counter << 2)];
			p_output[time + (counter << 2)] = 0;
		}

		// multiplication starts from here
		int index, row = 0;
		while (row < 4)
		{
			index = 0;
			while (index < 4)
			{
				p_output[time + (row << 2)] ^= multiply_number_number(constant[(row << 2)+ index], tempArray[index]);
				index += 1;
			}
			row += 1;
		}

		// end of multiplication
		time += 1;
	}
}